[PATCH v4 1/5] mtd: rawnand: meson: fix command sequence for read/write

Arseniy Krasnov
2023-05-15T09:49:54Z

This fixes read/write functionality by:
1) Changing NFC_CMD_RB_INT bit value.
2) Adding extra NAND_CMD_STATUS command on each r/w request.
3) Adding extra idle commands during r/w request.
4) Adding extra NAND_CMD_READ0 on each read request.

Without this patch driver works unstable, for example there are a lot
of ECC errors.

Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND flash controller")
Suggested-by: Liang Yang <liang.yang@amlogic.com>
Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
---
drivers/mtd/nand/raw/meson_nand.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 074e14225c06..2f4d8c84186b 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -37,7 +37,7 @@
#define NFC_CMD_SCRAMBLER_ENABLE BIT(19)
#define NFC_CMD_SCRAMBLER_DISABLE 0
#define NFC_CMD_SHORTMODE_DISABLE 0
-#define NFC_CMD_RB_INT BIT(14)
+#define NFC_CMD_RB_INT ((0xb << 10) | BIT(18) | BIT(16))

#define NFC_CMD_GET_SIZE(x) (((x) >> 22) & GENMASK(4, 0))

@@ -392,7 +392,7 @@ static void meson_nfc_set_data_oob(struct nand_chip *nand,
}
}

-static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
+static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms, int cmd_read0)
{
u32 cmd, cfg;
int ret = 0;
@@ -407,17 +407,29 @@ static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)

reinit_completion(&nfc->completion);

+ cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_STATUS;
+ writel(cmd, nfc->reg_base + NFC_REG_CMD);
+ meson_nfc_cmd_idle(nfc, 5);
+
/* use the max erase time as the maximum clock for waiting R/B */
- cmd = NFC_CMD_RB | NFC_CMD_RB_INT
- | nfc->param.chip_select | nfc->timing.tbers_max;
+ cmd = NFC_CMD_RB | NFC_CMD_RB_INT | nfc->timing.tbers_max;
writel(cmd, nfc->reg_base + NFC_REG_CMD);
+ meson_nfc_cmd_idle(nfc, 2);

ret = wait_for_completion_timeout(&nfc->completion,
msecs_to_jiffies(timeout_ms));
if (ret == 0)
- ret = -1;
+ return -1;

- return ret;
+ if (!cmd_read0)
+ return 0;
+
+ cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_READ0;
+ writel(cmd, nfc->reg_base + NFC_REG_CMD);
+ meson_nfc_drain_cmd(nfc);
+ meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
+
+ return 0;
}

static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf)
@@ -623,7 +635,7 @@ static int meson_nfc_rw_cmd_prepare_and_execute(struct nand_chip *nand,
if (in) {
nfc->cmdfifo.rw.cmd1 = cs | NFC_CMD_CLE | NAND_CMD_READSTART;
writel(nfc->cmdfifo.rw.cmd1, nfc->reg_base + NFC_REG_CMD);
- meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tR_max));
+ meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tR_max), 1);
} else {
meson_nfc_cmd_idle(nfc, nfc->timing.tadl);
}
@@ -669,7 +681,7 @@ static int meson_nfc_write_page_sub(struct nand_chip *nand,

cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_PAGEPROG;
writel(cmd, nfc->reg_base + NFC_REG_CMD);
- meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max));
+ meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max), 0);

meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_TO_DEVICE);

@@ -952,7 +964,7 @@ static int meson_nfc_exec_op(struct nand_chip *nand,
break;

case NAND_OP_WAITRDY_INSTR:
- meson_nfc_queue_rb(nfc, instr->ctx.waitrdy.timeout_ms);
+ meson_nfc_queue_rb(nfc, instr->ctx.waitrdy.timeout_ms, 1);
if (instr->delay_ns)
meson_nfc_cmd_idle(nfc, delay_idle);
break;
--
2.35.0